Maglev railroad to orbit

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TomKalbfus

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Apr 23, 2002, 3:51:26 PM4/23/02
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If we place a maglev railroad track on the Earth's equator and place a maglev
train that is 40,075 km long with 4,007,503 cars that are 10 meters long and
hooked all the cars up with spring hooks, this train would have no beginning or
end. Enclose this train track in a tunnel made up of telescoping air tight
segments and then remove all the air from this tunnel. Accelerate this train to
orbital velocity and then beyond and release the tunnel track from its anchors
and the entire tunnel track will rise up as the train speeds around the Earth
faster and faster. The tunnel segments will expand outward from each other as
the entire thing lifts off the ground. Passengers would ride upside down inside
the cars along with cargo. Once the track rises above the atmosphere, the train
would slow down to orbital velocity while speeding the track up to orbital
velocity. The track opens up and the train cars exit from the track and head to
their various destinations, unloading their cargo and passengers. The train
cars then hook up back on the track, the track tunnels close and seal, and the
train accelerates to twice orbital velocity slowing the track down to a
geostationary velocity. The train cars pull together forcing itself and the
track down until the track attaches back to its moorings on the Earth's
equator. Once secured to the Earth's surface, the train slows down and stops.
The train then unloads its cargo and passengers and receives new cargo and
passengers and the process starts over again.

Tom

Patrick Flannery

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Apr 24, 2002, 8:44:04 PM4/24/02
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"TomKalbfus" <tomka...@aol.com> wrote in message:
news:20020423155126...@mb-dd.aol.com...

> If we place a maglev railroad track on the Earth's equator and place a
maglev
> train that is 40,075 km long with 4,007,503 cars that are 10 meters long
and
> hooked all the cars up with spring hooks, this train would have no
beginning or
> end.

I'll say this for your plan- it is not lacking in ambition- last time I
heard of something on this scale of imagination, it was called a Dyson
Sphere- bravo!
Pat


Richard

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Apr 25, 2002, 4:16:51 AM4/25/02
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"Patrick Flannery" <fla...@daktel.com> wrote in message
news:ucekat9...@corp.supernews.com...
I can see a few teething problems with this one.....


TomKalbfus

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Apr 25, 2002, 12:53:49 PM4/25/02
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>I can see a few teething problems with this one.....
>

You just need to build a maglev track over the equator. The track needs to be
straight, flat and level and always remain directly over the equator. Most of
the equator goes over open ocean, but their are a few places that are of
concern. The equator crosses the the Andies montain range, though fortunately
not the thickest part, it goes over the amazon rain forest. The equator
intersects Africa and crosses through the Congo region and Kenya and we'll have
to cut through some more mountain on the east coast. Then there is Indonesia
and that's it, the rest is all ocean. The track would have to be elevated so we
don't have to cut a canal through each continent to keep the track level. We'll
have to destroy some mountains that get in the way, tunnels won't do since the
track must be able to levitate upwards. Over the oceans we'll need some oil
platform floatation devices to hold the track up above the oceans, and they
must compensate for the rise and fall of the tides.

Tom

gbaikie

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Apr 25, 2002, 9:02:48 PM4/25/02
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tomka...@aol.com (TomKalbfus) wrote in message news:<20020425125349...@mb-cv.aol.com>...

Yes, well, the previous post had it right about "a few teething
problems".
Also tidal effects are not confined to oceans- and the flatness of the
track would be technological marvel- less than a few inches over
hundreds of miles. With temperature variation, earthquakes, plate
tectonics- certainly "a few teething problems". And of course,
economically, it's hysterical.

MM

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Apr 26, 2002, 8:52:16 AM4/26/02
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> hundreds of miles. With temperature variation, earthquakes, plate
> tectonics- certainly "a few teething problems". And of course,
> economically, it's hysterical.

Nah, I'm sure the Europeans could get it done if that bad old U.S.A. would
get out of the way.


Alex Terrell

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Apr 26, 2002, 4:02:47 PM4/26/02
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Vintage Kalbfus. Should be in Sci Fi section.

Wouldn't it be easier to build the track in a straight line, so it
rose up out of the atmosphere. Cars could be accelerated in a straight
line till they reach orbital velocity outside of the atmosphere.

Alex

tomka...@aol.com (TomKalbfus) wrote in message news:<20020423155126...@mb-dd.aol.com>...

TomKalbfus

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Apr 26, 2002, 5:08:49 PM4/26/02
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The escape velocity of the Earth is 11.18 km/sec, If you had 1,638.4 km of
track and accelerated at 5 g for the entie length, you can reach a velocity of
12.8 km/sec. I was thinking about this and it occurs to me that maglev tracks
are expensive, about $1 billion per mile. Perhaps there is a cheaper
alternative. How about a hydrogen cannon that is 1,638.4 km long? Jules Verne
may have had the right idea except the muzzle of his cannon was too short.
Perhaps a cannon could be build that can accelerate a projectile along the
length of its muzzle at only 50 m/sec^2. A human riding inside this projectile
should be able to survive this acceleration. It should take 258 seconds to
accelerate down the length of the barrel. With such a long cannon, you could
have fans suck out most of the air in front of the projectile at a rate faster
that the air can replace it. Behind the projectile you pump hydrogen gas at an
ever increasing temperature and pressure so as to accelerate the projectile at
50 meters/sec^2.

Tom

Ian Stirling

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Apr 27, 2002, 2:46:12 AM4/27/02
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gbaikie <gba...@hotmail.com> wrote:
<snip>>
> Yes, well, the previous post had it right about "a few teething
> problems".
> Also tidal effects are not confined to oceans- and the flatness of the
> track would be technological marvel- less than a few inches over
> hundreds of miles. With temperature variation, earthquakes, plate
> tectonics- certainly "a few teething problems". And of course,
> economically, it's hysterical.

It doesn't have to be many hundreds of miles, a hundred miles would
get healthy humans to orbital velocity.
(at 25G: The "what doesn't kill you makes you stronger" theory of space
medicine)


--
http://inquisitor.i.am/ | mailto:inqui...@i.am | Ian Stirling.
---------------------------+-------------------------+--------------------------
If it can't be expressed in figures, it is not science, it is opinion.
-- Robert A Heinlein.

gbaikie

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Apr 27, 2002, 8:03:00 AM4/27/02
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tomka...@aol.com (TomKalbfus) wrote in message news:<20020426170849...@mb-cq.aol.com>...

> The escape velocity of the Earth is 11.18 km/sec, If you had 1,638.4 km of
> track and accelerated at 5 g for the entire length, you can reach a velocity of

> 12.8 km/sec. I was thinking about this and it occurs to me that maglev tracks
> are expensive, about $1 billion per mile. Perhaps there is a cheaper
> alternative. How about a hydrogen cannon that is 1,638.4 km long? Jules Verne
> may have had the right idea except the muzzle of his cannon was too short.
> Perhaps a cannon could be build that can accelerate a projectile along the
> length of its muzzle at only 50 m/sec^2. A human riding inside this projectile
> should be able to survive this acceleration. It should take 258 seconds to
> accelerate down the length of the barrel.

Probably better to shoot for a lower velocity and/or higher gees. If
you could achieve 7.0 km/sec this would get you most of way to orbital
speed. Since you are attempting to send passengers, it wouldn't be a
big deal to send passengers in a vehicle that could add extra needed
velocity, and have some docking ability at other end. You could also
use this cannon to ship cargo [without passengers] at higher
acceleration and end up with a higher velocity. At 5 gees and 140
seconds, you would need a barrel length of 490 km to get to 7 km/sec.
It's still fairly outragous as far as technically making it work and
quite expensive- easily +100 billion (but it would at least be a 1/3
the cost of a 1,638.4 km cannon). And using the same cannon, you could
accelerate cargo at say 100m/sec^2 (or more) for about 99 sec and get
a velocity of about 9.8 km/sec- this would get your cargo out to the
Moon.

With such a long cannon, you could
> have fans suck out most of the air in front of the projectile at a rate faster
> that the air can replace it. Behind the projectile you pump hydrogen gas at an
> ever increasing temperature and pressure so as to accelerate the projectile at
> 50 meters/sec^2.

Probably simpler to inject hydrogen and oxygen behind your payload and
do series of explosions [in order to maintain a constant high
pressure], and in front of payload simply have pure hydrogen gas at
say 70 F and around 1 atm with barrel end closed. Open barrel end, lit
the hydrogen, then inject oxygen gas and burn it in the hydrogen
environment of the barrel. What you want is hot hydrogen gas being
expelled from the barrel prior to the hypersupersonic shockwave of
your payload.

goh...@shell-3.enteract.com

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Apr 28, 2002, 4:10:30 PM4/28/02
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I wonder whether Tom's original levitating-in-two-senses train would be more
useful on a body which has much lower gravity (and is much flatter).
How about on Europa?

Also, just for a moment, I imagined the telescoping railroad on a very very
small asteroid, and got a silly image in which the maglev train cars have
been replaced by people on bicycles! Too silly? Ok, but my point is that
on a small enough body, maglevs and be replaced with more mechanical ways to
speed up the train cars. Hey, how about using an electric locomotive?
Maybe this has practical value but the expanding and contracting levitating
train track could serve as a very beutiful large-scale dynamic sculpture for
a wealthy spacefaring civilization. :-)

-- Eric Goldstein
eric at goldstein dot net


pete

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May 1, 2002, 11:27:20 PM5/1/02
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on Sat, 27 Apr 2002 06:46:12 GMT, Ian Stirling <ro...@mauve.demon.co.uk> sez:

` gbaikie <gba...@hotmail.com> wrote:
` <snip>>
`> Yes, well, the previous post had it right about "a few teething
`> problems".
`> Also tidal effects are not confined to oceans- and the flatness of the
`> track would be technological marvel- less than a few inches over
`> hundreds of miles. With temperature variation, earthquakes, plate
`> tectonics- certainly "a few teething problems". And of course,
`> economically, it's hysterical.
`
` It doesn't have to be many hundreds of miles, a hundred miles would
` get healthy humans to orbital velocity.
` (at 25G: The "what doesn't kill you makes you stronger" theory of space
` medicine)
`
Regardless of length, the tricky bit is when you get to the end of
the track. If you do all sorts of clever things to reduce atmospheric
drag inside your gun, then dump out the end into atmosphere, it will
be like hitting a brick wall. I have suggested (and I'm sure others
have before me) running a ramp eastward up the west slope of
Kilimanjaro, but that only gets you to 20k ft - maybe with a trellis
that adds another 0.5-1kft. I don't know what speed you can hit
at that altitude, but I don't imagine much more than say mach 5 or 6
before drag gets ridiculously ugly. One of the truly serendipitous
aspects of rocket launch is how the atmosphere thins helpfully
as the rocket rises and gains speed. Even so, it isn't a perfect
match, and acceleration is generally lower than tolerable to
get past the thick atmosphere without too high a speed (sorry being
a bit pedantic here, I realize most folk here know much more about this
than I do).

At any rate, you would want the inside air pressure toward the end of
your gun to gradually rise to match the outside pressure at the
muzzle, to avoid a nasty bump. I suspect that even using clever
ablative heat shedding to get around drag issues, trying to drive
a projectile fast enough that it could get from 20kft to orbit
without further propulsion beyond the end of the muzzle would
require such a muzzle velocity as to make the system unworkable
from a number of aspects. Not just how to get that velocity, but
the sonic boom inflicted downline from the muzzle.

And building a ramp to 3 or 4 times that altitude to get past the
serious drag problems is not within our capability, I don't think
anyone would challenge.


--
==========================================================================
vincent@triumf[munge].ca Pete Vincent
Disclaimer: all I know I learned from reading Usenet.

Ian Stirling

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May 2, 2002, 7:16:48 AM5/2/02
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pete <vin...@triumfunspam.ca> wrote:
>
> on Sat, 27 Apr 2002 06:46:12 GMT, Ian Stirling <ro...@mauve.demon.co.uk> sez:
<snip>

> ` It doesn't have to be many hundreds of miles, a hundred miles would
> ` get healthy humans to orbital velocity.
> ` (at 25G: The "what doesn't kill you makes you stronger" theory of space
> ` medicine)
> `
> Regardless of length, the tricky bit is when you get to the end of
> the track. If you do all sorts of clever things to reduce atmospheric
> drag inside your gun, then dump out the end into atmosphere, it will
> be like hitting a brick wall. I have suggested (and I'm sure others

There are ways.
If the sectional density of the launch vehicle is high enough,
the decelleration is managable.
Though this can mean sillyness like a vehicle that needs a 20m tungsten
nose, to keep up momentum.

Hanging the launcher from airships also seems possible at first
glance, but is probably not worth it.

My favourite launcher scheme these days is the beanstalk, assuming
nanotubes arrive cheaply sometime soon.

An interesting problem somewhat related to the electromagnetic catapult
is how to grab onto a cable that although it has a strength of 100 tonnes,
it's only on average 3mm in diameter.

And without causeing wear.

For a cable this size, it's almost certain that you can't transmit power
up it.
So, you've got to rely on beaming power to the ascent vehicle.

--
http://inquisitor.i.am/ | mailto:inqui...@i.am | Ian Stirling.
---------------------------+-------------------------+--------------------------

"When I use a word," Humpty Dumpty said in a rather scornfull tone, "It means
Just what I choose it to mean - neither more nor less." -- Lewis Carrol

pete

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May 2, 2002, 6:34:48 PM5/2/02
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on Thu, 02 May 2002 11:16:48 GMT, Ian Stirling <ro...@mauve.demon.co.uk> sez:
`
` My favourite launcher scheme these days is the beanstalk, assuming

` nanotubes arrive cheaply sometime soon.

Mine too, particularly the back-wheeling variety, dipping into high`
atmosphere, and lifting only to a medium height orbit - giving the
best combination of ease of meeting specs for both the tether and
the launch vehicle.

` An interesting problem somewhat related to the electromagnetic catapult


` is how to grab onto a cable that although it has a strength of 100 tonnes,
` it's only on average 3mm in diameter.
`
` And without causeing wear.
`
` For a cable this size, it's almost certain that you can't transmit power
` up it.
` So, you've got to rely on beaming power to the ascent vehicle.

`
I can't really conceive of using a 3mm dia. cable, even if it has
been thoroughly demonstrated to work. I would want to have something
that my primitive brain was ready to believe could do the job. I
imagine something about >2cm dia., including some sort of protective
coatings, ending in a big teardrop coupling vaguely reminiscent of
inflight refueling hose. The coupling would have a bunch of active
components, including a locating transmitter, and probably some
kind of glider auto-stabilizing wing surfaces.

Ian Stirling

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May 3, 2002, 10:26:58 AM5/3/02
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pete <vin...@triumfunspam.ca> wrote:
>
> on Thu, 02 May 2002 11:16:48 GMT, Ian Stirling <ro...@mauve.demon.co.uk> sez:
> `
> ` My favourite launcher scheme these days is the beanstalk, assuming
> ` nanotubes arrive cheaply sometime soon.
>
> Mine too, particularly the back-wheeling variety, dipping into high`
> atmosphere, and lifting only to a medium height orbit - giving the
> best combination of ease of meeting specs for both the tether and
> the launch vehicle.
>
> ` An interesting problem somewhat related to the electromagnetic catapult
> ` is how to grab onto a cable that although it has a strength of 100 tonnes,
> ` it's only on average 3mm in diameter.
> `
> ` And without causeing wear.
> `
> ` For a cable this size, it's almost certain that you can't transmit power
> ` up it.
> ` So, you've got to rely on beaming power to the ascent vehicle.
> `
> I can't really conceive of using a 3mm dia. cable, even if it has
> been thoroughly demonstrated to work. I would want to have something
> that my primitive brain was ready to believe could do the job. I

I was meaning for a beanstalk.
I'm hoping that sometime soon, someone will work out the correct incantation
to produce reasonably long single-wall nanotubes, in quantity at lowish
(under $1000/g or so) prices.

You then launch a shuttle-full of cable, which works out to perhaps a
1ton paayload.

Then you start shipping cable up the cable, in order to bootstrap it.

In 5 doubling times (which may vary from a few weeks to over a year,
you have a system that can take several shuttle-class payloads to
GEO+ in a day.

Now, you start building other tethers.

(These figures assume broadly 100GPa, density 1.5 single-wall long nanotubes.)

Any other approach (bar orion) to significant space capacity seems
to be either using huge fleets of (possibly reusable) rockets, or
bootstrapping from external resources using small inputs.

Either slow or expensive.

--
http://inquisitor.i.am/ | mailto:inqui...@i.am | Ian Stirling.
---------------------------+-------------------------+--------------------------

Q: What do you call a train that doesn't stop at stations?
A: Thomas the Bastard. -- Ben

Paul F. Dietz

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May 5, 2002, 7:33:53 PM5/5/02
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gbaikie wrote:

> Probably simpler to inject hydrogen and oxygen behind your payload and
> do series of explosions [in order to maintain a constant high
> pressure], and in front of payload simply have pure hydrogen gas at
> say 70 F and around 1 atm with barrel end closed.

Even simpler: the ram accelerator.

http://www.aa.washington.edu/AERP/ramac/ram.html

Paul

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